Know what you're getting in to. It is an extremely difficult venture. We have been in the business for 4 years, have invested over 500k and are still struggling. The money comes in and goes right back out...and we are selling over 25k worth per month. There are constant problems. When I started it was for personal use, did it out of my garage and sold the excess oil to friends. I had a handful of accounts and it was kind of a fun (although dirty) hobby. Once I crossed the line and turned it into a business the nigtmares began. I am a entrepreneur by nature, have a college degree, and have started many sucessful businesses.
Some hurdles you will face...
-CONSTANT equipment failures (especially pumps). Sometimes failures will involve catastrophoic oil spills.
-You WILL spill oil (Honestly, if you can find just ONE person that hasn't I would be astonished and/or call them a liar).
-When you're a legitimate business, these spills will draw attention from the city, county, state, EPA, haz-mat, and fire authority. We know this as used cooking oil, they see it as a flammable hazardous material...especially in quantities over a tote. (and you know these boy's wont show up without leaving a very healthy fine, even if they don't shut you down).
-Your landlord, neighbors and community will not welcome you (even if it's a "green" business). WVO smells bad, looks bad, and people are freaked out about the storage of it.
-You can't sell oil in volumes under 6,000 gallons to any serious customer...and they really want you to send a load every week. The transition from small hobby collector to small business is huge. Even 6,000 gallons per week is considered a "small" oil producer to industry. BTW, the average mom and pop restaurant provides you with 30 gallons per month useable...do the math.
-You will not be able to sell all of the oil you collect. About 20% is animal fats or hydrogenated oil, trash and food scrap. People are only interested in the 'black oil' -or vegetable oils. You must figure out how to get rid of this. You may have to pay a septic pumper to take it away, which will eat into your profits.
-You have to filter 6,000 gallons per load. (this requires large expensive filtering equipment). You arent going to do this with blue jeans or small filter housings).
-You need to load a tanker or flexi container in 2 hours in most cases. The driver will be sitting there waiting for you to finish and will start charging you if it goes over by alot of time...not to mention they will be frustrated and upset.
-You will not be able to get permitted in a small industrial strip facility. You need a freestanding building with no common wall neighbors. Fire Departmant thinks 'biodiesel' when they think grease and get freaked out because there have been several fires and explosions over the past 4 years due to 'homebrew' disasters mostly involving cheap plastic conebottom reactors and/or the inproper storage of methanol. Especially if you heat oil, which you will need to do in order to filter.
-Don't think about producing biodiesel for a business if you do not have 1 million+ available for investment...this must be done properly.
-Don't even think about stealing oil, you will be prosecuted. The big boy renderers spend endless amounts of money chasing down and prosecuting oil theifs. I know a guy that was sued once for 750k. Do it right and ethically, or don't do it at all.

There are many, many more reasons why this is truly the most difficult business to get started in. It seems simple, I know. That is why I got into it. I'm not trying to scare you off, I just know many people who have gone bamkrupt over this venture (why do you think you see several posts offering to sell used collection/processing equipment). People selling you equipment will tell you it's easy, no problem, etc. They are either making false claims, are not in the business themselves, or are trying to offload their used garbage because they are out of business. I do not know you, know where you are located, and am not trying to sell you anything. I just am trying to help out a fellow greaser. If you still want to get started, best of luck. Just make sure you have a steady income to pay your bills for a while until this starts making some sort of income, and 100k to invest to get started. You can be successful..it's just that the odd are very bad that you will.

I agree there are so many companies trying to make it in this business and I was one of the I lasted a year and a half before havining to throw in the towel. It is such an expensive business and so competative. I've seen companies come and go and in the end even my 200k start up proved to be too little. I'd think twice if I were you.